Electrically-operated track switch



April 20,1926. 5 1,581,607

' G. A. MEAD ELECTRICALLY OPERATED TRACK SWITCH Filed Dec. '7, 1923 2Sheets-$heet 1 April 20, 1926.

G. A. MEAD ELECTRIGALLY OPERATED TRACK SWTCH Filed Dec '7, 1925 2Sheets-Sheet 2 In WI Patented Apr. 20, 1926.

UNITED STATES PATENT OFFICE.

GEORGE A. MEAD, or MANSFIELD, orrro, AssIenoR TO THE OHIO BRASS COMPANY,

on MANSFIELD, OHIO, A oonronnrrou" or NEW JERSEY.

ELECTRICALLY-OPERATED TRACK SWITCH.

Application filed December To all whom it may concern:

Be it known that I, GEORGE A. MEAD, acitizen of the United States ofAmerica,residing at h Iansfield, in the county of Richland and State ofOhio, have invented certain new and useful Improvements in anElectrically-Operated Track Switch, of which the following is aspecification.

My invention relates to an electrical system for operating switches andis particularly adapted to the operation of track switches by theoperator upon a car.

One of the objects of my invention is to provide means forauton'iatically operating the track switch fromthe car through themedium of the motor controller when thrown to either power on or poweroil the motors.

Another object of my invention is to supply current to'the system for apredetermined period of time and regardless of the position of the carafter having once set the system in operation.

Another object of my invention is to prevent the track switch beingthrown to the wrong position afterbeing initially set to the correctposition;

A still further object of my invention is to prevent the burning out'ofthe track switch operating mechanism.

A still further object is to prevent the breaking of destructive arcsbythe current collector or trolleywheel. y

Other objects will disclose themselves as further disclosure of myinvention is made herein.

My invention resides in the new and novel construction, combination andrelation of various parts andicircuits herein described and shown in thedrawings.

In the drawings accompanying this specification: i

Fig; 1 shows a diagrammatic scheme of the circuits employed ina car andwhich are taken into account in the operation of my invention asmorefully described here- I inafter.

Fig. 2 is a schematic'drawinoof my in vention showing the relation ofthe various parts and circuits when'the system is in normalcondition,that is, before and after its operation for positioning the trackswitch.

7, 1923. Seiiai N0. 679,099.

The switch tongue, however, may

be in any of its positions.

Fig. 3 is a schematic drawing of my invention, showing the arrangementof the parts and circuits immediately after it has been set in operationby the car operator turning his controller tov power 01f,

Fig. i isa schematicdrawing of my invention showing the arrangement ofthe V21;-

rious' parts and circuits after a predetermined time after the systemhasbeen set in operation by the car operator setting his controller topower off position.

Fig. 5 is a schematic drawing showing the arrangement of parts andcircuits when the system has been set in operation by the operatorset-ting his controller to the power on position.

Referring to Fig. 1, it is the object of my invention to provide asystem 'by means of which the track switch is automatically andelectrically operated to its straight ahead or curve position as may bedesued by the car operator merely applying .power on or power off to hismotors by means or. his regular motor controller. The system utilizesthe principle that when the controller is set to power off no current isflowing through the. motors and when the controller is set to power onheavy current will flow through the motors. Theflow and non-flow ofcurrent is made use of in the operation of the system for setting inoperation and properly positioning the switch tongue. There are othercurrents flowing through the car motor which must be taken into accountin the designing of the system and which are not under the control ofthe car operator, or rather are not controlled by the car controller.These are what are known as the heat, light, air compressor circuit,etc, and which shall refer to as the. auxiliary car circuits.

In Fig. 1 l/V represents the trolleywheel' or current collector and Trepresents the trolley pole by means of which the current collector ismounted upon the car. H indicates'the heaters, indicates the lights andF indicates the air compressor circuit and these circuits when all inoperation, together with possibly others, may carry a total of aconsiderable amount of current.

ing thereover.

The motors for moving the car are indicated by M and the switch by whichthe current through the motors iscontrolled is indicated by C. All ofthe circuits within the car are connected to the ground.

In the preferred embodiment of my invention, which is shown in normalcondition in Fig. 2, P indicates a trolley pan -which is positioned inconnection with the trolley conductor 1 so that the current collectormay pass from the trolley wire on to the pan P and out of engagementwith the trolley conductor and pass off .ofthe pan P and back intoengagement with the trolley conductor 1. The pan P comprises twolaterally spaced parallel contact members 2 and 3 which are normallyinsulated from each other, but so positioned that the current collectormay bridge the two in passi I employ av track switch S which is providedwith a switch tongue l. The electrical operating mechanism for thetongue 4 comprises. two solenoids 5 and 6, one terminal of each solenoidbeing connected to the ground G through the conductor 7. Reciprocallyoperating within the solenoid is a plunger '8 which is drawn in whensolenoid 5 is energized and drawn out when solenoid 6 is energized andwhich is connected to the switch tongue and therefore moves the tongueto one or the other of its positions.

I also employ an electrically operated switch A, which I will term aselector switch,

.as its function isto place one or the other.

of the solenoids 5 or 6 in circuit when the current collector engagesthe pan P. The switch A is provided with a coil 9 mounted upon an ironcore and having one terminal connected to the trolley'wire 1 by theconductor 10, and having itsother terminal connected to the contactmember'3 by means of the conductors 11 and 12. The coil 9 Iprefer tomake of a few turns of heavy wire as it must withstand a heavy currentflowing therethrough and it must also have its ampere turnssoproportioned that it will operate to raise the switch arm 13 when thecontroller C is turned to the power on posiytlOIl with the collector inengagement with the pan P and which will not raise the arm 13 when thecontroller is turned to the power ofi' position. 'Also the ampere turnsmustbe so adjusted that the current flowing through the auxiliarycircuits and which It will be seen that the 0011-,

C, motors M to the ground at the same time the contact member 2 will beelectrically connected to the trolley wire 1 through the medium of thecurrent collector. The switch A is also provided with two contacts 14and 15 and the switch arm 13 is normally in engagement with the contact15 so that the selector switch is normally set for connecting the systemto the solenoid 5 and will so remain set if thecollector engages the panwith power oif. It will also be seen that when the switch arm 13 engagesthe terminal when the collector engages the pan P that the solenoid (3is placed in circuit withthe system. I also employ an electricallyoperated switch B whichis provided with a coil 16 mounted upon amagnetic core and has one terminal connected to the contact member 2 bythe conductor 17, and the other terminal connected to the ground G bymeans of the conductor 18. It is not necessary. that the conductor 18shall be connected directly to the ground, but it may be connected toany other point in the system which will give it a ground connection andwithout interfering with the functioning of the various parts asrequired. The resistance of the coil 16 may be sufficiently high so thatonly a small current flows therethrough, therefore, when the collectorleaves the pan P only a slight arcing will take place.

It will be evident that when the pan P is engaged-by the currentcollector with either power on or power oil that current will flowthrough the coil 16 thereby energizing the same and picking up the arm19, and

that the arm 19 will be held in a raised position by the coil 16 as longas the current collector engages the pan P. The switch arm 19 isconnected to the trolley conductor 1 by means of the conductors 20 and21. The conductor 21 can however, be connected to the conductor 10 or itmaybe connected to the contactor 3 although I do not prefer this latterconnection as then any current flowing through the conductor 21 willflow through the coil 9 and will merely add to the auxiliary car circuitcurrent and, therefore, tend to make it more difficult to properlyadjust the winding of the coil 9. When the arm 19 is raised it engagesthe contacts 22 and 23. The contact 23 is connected by the conductor 24to one terminal of the coil 25 and the other terminal of the coil 25 isconnected to the arm 13 by the conductor 26. It willbe seen thatwhenever the arm 19 engages the contact 23 and current is flowingtherethrough that the coil 25 will be energized and as coil 25 is notwound to act differentially with coil 16 it becomes a holding coil andwill maintain the arm 19 in engagement with the con tact 23 whenevercurrent is flowing there through and regardless of whether current 14throughthe application of power on maintain the branch circuit from thecontact;

15 to-the solenoid .5 normally closed and to open this circuit after apredetermined time after the switch B has closed; The switch comprisestwo coils 27 and 28 dilterentially connected and ot comparatively highresist-Q ance so as to permitonly a small current to pass therethroughas this current flows through-the solenoid and must, therefore, noteffect the operation of the solenoid. One end of each coil 27'and' 28is' connected to the switch arm 29 through the conductor 30, and theswitch arm 29 is connected to'the remaining terminalot the solenoid 5 bythe a conductor 31. It willfbe noted that the conductors 30, 31,solenoid 5 and conductor 7 term aground connection for the coils 27ancl'28. The remaining terminal of coll 28 is connected to the source ofpower through the conductors-32 and 21 aud it will be evident that thecoil28 isnormally energized and will therefore, attract and maintain thearm 29 in-engagement with the contact 38 under normal conditions.terminal of the coil 27 is connected to the switch arm 13through theconductor 34 and r it is evident that the coil 27 will have a connectionwith the source of power whenever the arm 19 i'sclosed through theconductors 34, 26, coil 25, conductor 24, arm 19 and ronductors and 21.When, however, the arm 19 is closed and the arm 13 engages the contact15the arm 29willbe of substantially the same polarity as the trolleyconductor'l V as-these two are gonnected through a low resistancecircuit comprising the elements 521. 2c, 19, 24, 25, 2e, 13, 15, 35 andas. lit will be evidentirom this that the conductors 30 and 82 will beconnected to points of electrically equal polarity, therefore, thecurrent which has been flowing through the coil 28 will cease as therehas been substan l'ially a shunt placed across the terminals of thiscoil and as the same is true of the coil 27through its connection withthe arms 13 and 29 no current will flow through thiscoil and, therefore,the arm 29 will drop after a predetermined timelag due to thedissipation of residual magnetism in the core or other holding means. Assoon, however, as the arm 29 has dropped the difierence 0t potentialbetween'the arm 29 and the trolley conductor 1 will be a. maximum andalso the same is true between the'arm 13 and the arm 29, and currentwill flow through each coil 27 and 28 but in opposite directions, andthe arm 29 will be maintained in open position through theditterentialaction ot' the enerheld in .a closed position.

arm 19 is closed and current is flowing through the coil 25 the coil 25will function 'as a. stick or holding coil, and 'it. willot Theremaining fgized coils 27 and 28 so long as the arm rl9 remains closed.

It will beevident that when the switch has been closed by a currentcollector engagin'gthe pan P with powergoif andenergizing the coil 16,that the arm 19 will be. placed in engagement with'th'e contact '23,-and current will then flow through the sole? noid-5 and the plunger 8will be drawn in-' wardlyand the track switch tongue moved to thestraight ahead position. It will also be evident that as long astheIcontactor engages the pan witli.'power oil that the coil. 16. willvbe energizedand the arm 19 As soon asthe itself maintainthe arm 19 in ar-aisedposi tion as long as current 18' flowing through the circu t;

B5 The circuit will remain closed as I long as the arm 29 is inengagement with thecontact 33, but, as already explained, after a v Ipredetermined time after the closing otwthe arm 19 the arm 29 will openthereby opening the circuit through the coil 25 and t-hesolenoid 5, andthe arm 29 will drop providing the contactor is in engagement with thepan P.' If it is, the arm-29 will be maintained after-the opening of theswitch C, as just described, is shown in Fig. 4. It the contactor shouldbe off the pan before the switch 29 opens the current flowing throughthe coil 25"will maintain the arm 19 closed and the arm 29 will functionto open the circuit through the coils 25 and 5, and as soon as thistakesplace the coil 25 will become deenergized and the switch: arm 19 willdrop,zbut the arm 29 will beimmediately raised upon the dropping of thearm 19 as the coil 27 ot the switch C will be deprived of its energizingcurrent, but the current will continue to flow-through the coil 28 whichwill pickup the arn'i29and1the sys tem will then be returned to itsnormal condition. a i i Vhile current is flowingthrough the system, asjust described, with the arm 13 in engagement with the contact 15current will also flow through the coil-36 as it has its terminalsconnected to the conductor and As a terminal 14 is connected tothe-re'maining terminal of the solenoid 6 by the con ductor 411, thisfurnishes a ground connection for the coil 86 which receives current 7from the conductor35. connected that it acts difiiereutially tothe coil9 when; it is energized with the arnrlS :The coil 36 is so inengagementwith ithe contact The:

ampere turns, however, of the coil 36 are so proportioned that the'coil36 will not pick In" order to properly to-affect solenoid: 6, Iinayintroduce in the circuit an external resistance 38 by means of which theampere turns can be properly ad-' justed in the coil 36.

It now a current collector thepan P with power on, asalready explained.heavy current will fiowi through the coil 9 which will pick the arm1311p and into engagement with the contact 14.

This prevents the How of any ciugrent through the coil 5, but permitsthe flow-of current through thefcoil 6 when the arm 19 has been pickedup through the. energizing of the coil 16 whereu'pon the plunger Sjwillbe moved outwardly and the switch tongue 4 moved to the curve position.The-rela tion of the various parts immediately afterthe collector hasengaged the pan P with power on 14 and the arm 19 closed, as justdescribed, current will also flow through the. coil 36, but in theopposite direction from that previously described and in'the samedirection as current through the coil 9 so that the two will worktogether and both act as holding coils while the'current collector ispassing across the pan P with power on, but as soon as thecollectorleaves the panP then the-coil 36 is the only holding coil tomains tain the arm 13 in engagement with the con-.

tact 14. The ground for the 'coil 36 when the arm 13 engages the contactlit is byway of the switch arm 29. As soon asthe arm 19'closes theswitch C will start to function to drop the arm 29, but will dosothrough" .the'arm 19 to drop. Immediately'uponthe dropping of the arm19 the coil 27 is deenergized and the continued energization: of thecoil 28 will pickup the arm 29, returning thesystem to. its normalcondition as shown in Fig.2.

It has already beenexplained as to the flow of auxiliary car-currentsthroughthe coil 9 which have a tendency, itsuflicientlylarge, to pick upthe arm 13 when the 001- ,is shown diagrammatically in Fig. 5.1 3, pWhen the arm 13 isclosed on the contact I scribed.

lessthe ampere turns ofthe' coil 9 are so proportioned'that this-willnothappen. It up the arm 13, but will act only as a holdingcoil for thearm 13.

adjust the ampere turns in this circuit,whiclr is of comparatively highresistance soas not has also been explainedin'regard to the difterentialaction of the coils 9 and 36 when the collectorengages the pan withpower off. It-will be evident trom this that the differential action 0tthe coil 36 when the system operates with power oli". is beneficial asit tends to neutralizeany picking up I p -etlect of thecoil 9.4. shouldengage It the-collector should engage the pan P witlrfpo'wer on? andshould come to rest with the. collector engaglngthe pan,.1t will 'benecessary for the operator to throw his controller to power on.in orderto proceed off the pan, and in. this case the coil 9 might besuthciently energized to pick up the arm 13 and current would then flowthrough the solenoid 6 thereby setting the switch in the wrong directionas the arm '19, remains closed VBHtIL-fllll flow of current through thecoil 9 and prevent .suiiicient energization of the switch A. to pick upthe arm 13. In addition to the shunt justdescribed, the coil36 which'isnergized until the arm 19 opens, acts as a diiterential to the coil 9and,.thereiiore, it willv help to prevent a. pick up of the arm 1.3 whenthe operator turns his controller to power on 'underthe conditions.justjdehas dropped, and then the current cannot flow to the solenoid 5.1

There will beemany changes and modifications in the system justdescribed, such as possibly rearranging some of the connections andcircuits, "but-which will stillproduce a system working within thescopeofmy invention; I

I claim-- 1 y 1. A switch operating system comprising in combination, atrolley conductor, a pan provided withtwo contact members to be engagedby a current-collector, an electrically operated track switch, a dividedpower circuit leadingto said-switch, an electrically operated selectorswitch connected to one of the contact members for controlling the saidThe shunt or shortcircuit tothe.

Tim

means controlling the selector switch and.

cooperating with the opening means to open the other divided circuitafter the. opening means has opened,

v 2. A switch operating system comprising in combination, a trolleyconductor, a pan provided with a pair of contact members to be engagedby acurrent collector, an electrically operated track switch, a branchedpower circuit leading from thGtl'OllGY con ductor to the track switch,an electrically operated selector switch for controlling the powercircuit to operate the track switch to aidesired position, a normallyopen. switch to open and close the power circuit, means for closing thepower circuit and means for holding the switch closed while current tooperate the track switch is flowing in the power circuit switch,normally closed means for opening one of the branch circuits after apredetermined time after the normally openswitch has been closed, andmeans cooperating with the last said switch and with the selector switchto open the other branch circuit after the normally closed switch hasopened.

' 3. A switch operating system comprising in combination, a trolleyconductor, a pan to be engaged by a current collector, an electricallyoperated track switch, a normally open branched pgwer circuit leading tothe track switch, an electrically operated means normally closing .oneof the branch circuits andopening the same after a predetermined timeafter the collector engages the pan, an

electrically cperated switch to close a second branch circuit whenthecollector engages the pan with power on, and means lnterconnectingthejswitch and electrically operated means to control theirrelativeoperation to open the second branch circuit after apredetermined time but after the first branch circuit has opened. a

4. A switch operating system comprising in combination, a trolleyconductor, a pan to be engaged by a current collector, anjelectricallyoperated track switch, a. normally open branched operating circuit toconduct an operating current to the track switch, a

selector switch to control the said circuit so" that the track switchwill be operated in one direction or the other when the collectorengages the pan with power on or power off, electrically controlledmeans normally closing one of the branch circuits and adapt- .ed to openafter a predetermined time after current to the operating circuit, andmeans controlling theother branched c rcult to ,open "the same after thefirst trically controlled means.

5. A switch operating system comprising in combination, a trolleyconductor, a pan to be engaged by a current collector, an electricallyoperated track switch, a normally open branched operating circuit toconduct an operating current to the track switch, a selector switch tocontrol the said circuit to control the direction of operationof thetrack switch branch circuit has been opened by said elecwhen thecollector engages the pan with power on or power off, and electricallycontrolled means to open one branchclrcuit aiter the collector engagesthe pan w1th power oil and to open said branch circuit v and control theopening of another branch circuit after the collectorengages the panwith power on.

6. A switch operating system, comprising in combination,a'trolleyconductor, a pan to be engaged by a current. collector, anelectricallyoperated track switch, a normally open branched operatingcircuit to conduct an operating current to the track switch,*a selectorswitch to control the saidcircuit to control the dlrectlon of operationof the track switch when the'colle'ctor engages the pan with poweron orpower olf, electrically controlled means to open one branch circuitafter the collector ens gagesthe pan with power off and" to open saidbranch circuit and control the opening of another branch circuit afterthe collector engages the pan with power on and means to normally holdthat portion of the power circuit leading to its branch circuits openand to close the same when the collector engages the pan.

7. A switch operating system comprisingin combinatiom'a trolleyconductor, a pain, to be engaged by a current collector, an'electrically operated track swltch, a normally open power circuit to conductcurrent to the track switch, a selector switch controlling said circuitto operate the track switch to proper position when the collectorengages the pan with power on or power off, an electrically operatedclosing switch to close the power circuit when the collector engages thepan, a holding coil on said closing switch and energized'by the currentin said power circuit to hold the closing switch closed after, beinginitially closed and means tor de-energizing the holding coil after apredetermined time after. the closing switch is closed. I

8; A switch operating system comprising in combination, a trolleyconductor, a pan to be engaged by a current collector, an

track switch to a predetermined position when the collector" engages thepan with power off or power on the car motors,

. means to closethe selector switch to normally connect one branchcircuit to the power circuit, means operating the selector switch toconnect the other branch circuit to i the power circuit when thecollector engages the pan with power on, means controlling the selectorswitch tending to prevent the selector switchoperatingto close thesecond mentioned branch circuit when the power circuit and first branchcircuit is closed and to hold the second branch circuit closed 5 afterbeing initially closed and means to control the opening and closing ofthe power c rcuit to the branch circuits.

bination of a trolley conductor, a, pan, an electrically operated trackswitch, a power circuit, branch; circuits leading to the track switch, aselector switch connecting the power circuit to the branch circuitstooperate the track switch to diflterent positions.

electrically operated means cont-rolling one branch circuit to open itafter a predetermined time of flow of current therethrougn and meanscontrolling the other branch ci r wit to open the same after it has beenclosed by the selector switch, the last said means being controlled bythe means controlling the first said branch circuit,

10. In a switch operating system, the combination of, a trolleyconductor, a pan coinprising two contact members to beengaged by acurrent collector, an electrically operated track switch S, a selectorswitch A of by connecting to one or the other 0t two branch circuitsleading to the track switch, a normally open power circuit connectingthe trolley conductorwith the selector switch, an operating coil 9 forthe switch A connected to the trolley conductor and to one contactmember and energized suiiiciently to operate the switch A with power ononly; a switch B to close the power circuit when the collector engagesthe pan andhaving an operatingfcoil connected to the other contactmember on the pan and having a ground connect-ion andhoperating to closethe switch B and hold it closed while the collector engages the pan, theswitch 13 also having a coil operating tohold the switch B closed whilecurrent is flowing in the power circuit and deriving its operatingcurrent from the power circuit; a switch C normally closing one of thebranch circuits leading to. the switch S which operates the switch S"with power off, the

switch C having two operating coils so connected that one holds theswitch 0 normally closed and both hold the switch. open while the switchB is closed and also operating to open the switch C aftter apredetermined time after theswitch B is closed; an operating coil forthe switch A so ,connecte crating to hold the switch A in the power onposition when the switch ,A has been operated to the power on positionandas long as theiswitch C is closed.

11. In a switch operating system, the comv bination ot,a trolleyconductor, apan coin- 9. In a switch operating system, the com-lInect-iiig to one or the other of two branch circuits leading-tothetrack switch, a normally open power. circuit connecting the trolleyconductor with the selector switch,

an operating coil 9 for theswitch A connected to the trolley conductor adi one 0011- tact member and energized sufficiently to operate theswitch A with power on only; a switch B to close the power circuit whenthe collectorengages the pan and having an operating. coil connected tothe other contact member and having a ground connection and operating toclose the switch Aand hold it closed while the collector engages thepan, the switch A also havinga'coil operating to hold thesw'itch'Aclosedfwhile current is flowingin the power circuit and deriving itsoperating current from the power circuit;

a switch C normally closing' one of the branch circuit'sleading to theswitch S which operates the switch S-with power oii, the

V switch C having two operating coils so connected that one holds theswitch G normally clo'sedand both .hold the switch open while the switchBis closed and also operating to opentheswitchC after a predeterminedtime after the switch B is closed; an operating coil for the switch A soconnected as i to be energized whenever the system has been set inoperation and in which the currentflowtends to counteract the'efitect ofcurrent in the coil -9 when the system is 'working power off and tendsto assist the current in the coil 9 when the system is working power on,thesaid coil also operating to hold the switch A in the power onposition when the switch A has been operated to the power on positionand as long as the switch C is closed, means con "trolleci by the switchB toprevent the switch bination of, a source of power, a contact deviceto be engaged by a current collector, an electrically operated trackswitch, a selector switch to control the operation of the track switchto a predetermined position whenthe collector engages the contact devicewith power on or power off and normally held in the power oil? position,and circuits connecting the parts for the above operation, the selectorswitch having a coil to operate it to the power on position and alsohaving an operating coil in which the current flows in one directionwhen the system works power on and in the other direction when thesystem works power off.

13. In a switch operating system the combination of, asource of power, acontact device to be engaged by a current collector, an electricallyoperated t-r ck switch, a selector switch to control the operation oi"the track switch to a predetermined position.

when the collector engages the contact device with power on or power OHand normally held in the power off position, and circuits connecting theparts for the above operation, the selector switch having a coil tooperate it to the power on position and also having an operating coil inwhich the current flows in one direction when the system works power onand in the other direction when the system works power off, thedirection of How being determined by the selector switch being in thepower on or power oflf position.

14. A switch operating system in combination, a trolley conductor, a panto be engaged by a current collector, an electrically operated trackswitch, a normally open ener- I gizing circuit to conduct an operatingcurrent to the track switch, an electrically operated selector switch tocontrol the direction of movement of the track switch, a switch Bmaintaining the energizing circuit normally open, means for closing theswitch B when the collector engages the pan and to hold the switch Bclosed while the collector engages the pan and means dependent upon thecurrent flowing through the track switch for holding the selector switchclosed as long as an operating current flows in the energizing circuit.

15. A switch operating system comprising in combination, a trolleyconductor, an electrically operated track switch, a normally openenergizing circuit leading to the track switch, a circuit controllingmeans operated automatically when a car cooperates with the system totransmit current to the track switch to operate the switch to the properposition and an electrically controlled switch operative when the carcooperates with the system to first close the circuit and maintain itclosed while current is flowing therein to operate the track switch andthereafter so long as the car cooperates with the system.

16. A switch operating system comprising in combination, a trolleyconductor, a pan to be engaged by a current'collector, an electricallyoperated track switch, a normally dead energizing circuit connected tothe track switch, a circuit controlling means for the energizing circuitoperated automatically when the collector engages the pan to operate theswitch in the proper direction, means other than the collector toenergize the circuit when and while the collector engages the pan, andmeans to maintain the last said means operative and depending foritsopera-tion upon an operative current flowing through the track switch.

17. A switch operating system comprising in combination, a trolleyconductor, a pan to be engaged by a current collector, an electricallyoperated track switch, a normally dead energizing circuit connected tthe track switch, a circuit controlling means for the energizing circuitoperated automatically when the collector engages the pan to operate theswitch in the proper directiommeans controlling the energizing of saidcircuit comprising means operated by the collector engaging the pan tosupplycurrent to the said circuit when and while the collector engagesthe pan and independent means operated by current derived from the saidcircuit while an operating current is flowing through the track switch.

18. In a mechanism of the class described, a normally open circuit, anelectrically operated switch to close the circuit, a coil for operatingthe switch, means to be engaged and energized by the current collectoron a car and connected to the coil, a coil for holding said switchclosed and deriving its current from a trolley conductor and a normallyclosed switch to open the circuit at another point after a predeterminedtime after the circuit isclosed.

19. A switch operating system comprising in combination, a trolleyconductor, a pan, to be engaged by a current collector, an electricallyoperated track switch, a normally open power circuit to conduct currentto the track switch,.a selector switch controlling said circuittooperate the track switch to proper position when the collector engagesthe pan with power on or power off, an electrically operated closingswitch to close the power circuit when the collector engages the pan, aholding coil on said closing switch to hold the closing switch closedafter being initially closed and means for tie-energizing the holdingcoil after a predetermined time after the switch is closed.

20. switch operating system comprising an electrically operated trackswitch, a branchedvoperating circuit therefor, a controlling switch forpositioning said branched circuits and having an operating coil andconnections to said coil, means to control the branches respectively ofsaid branched circuit after a predetermined time.

21. A switch operating system comprising in combination, an electricallyoperated track switch, a branched operating circuit, a controllingswitch therefor having an operating and a holding coil, means todeenergize the operating coil after it has functioned to operate thecontrolling switch and means to open the branches of the branchedcircuit after a predetermined time, i

Intestiniony whereof I amx my signature.

GEORGE MEAD.

